This one gets the warning: Love of the natural world can often lead to chronic grumpiness and foul language.
Doom and gloom is not recommended but sometimes we have to hear it.
Grist published a good story detailing the personal, and commercial, impact of ocean acidification. Look at how it effects a family oyster business in Oregon as well as the consumer.
Serious: "I'm afraid the ocean will be dead long before we have to worry about the other implications of global warming," Barton (scientist in the story) says quietly. "I didn't believe any of this stuff three years ago. I was always skeptical about our global models ... But ocean acidification is pretty cut and dried for me now. You see it every day. You can't escape it."